21 terms

Translation and Mutation II

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rRNA
The two ribosomal subunits (large and small) are made of proteins and ____
p
the ___ site holds and tRNA that carries the growing polypeptide chain
a
The ___ site holds the tRNA that carries the next amino acid to be added to the chain
e
the ___ site is the exit site, where discharged tRNA's leave the ribosome
initiation, elongation, termination
The 3 stages of translation are (in order)
initiation
Proteins called ____ factors bring in the large subunit that completes the translation initiation complex
a
Termination occurs when a stop codon in the mRNA reaches the __ site of the ribosome
water
The ____ factor causes the addition of a water molecule instead of an amino acid during termination
polysome
A number of ribosomes can translate a single mRNA simultaneously, forming a ___
polyribosome
A ____ enable a cell to make many copies of a polypeptide very quickely
true
Ture or False: Translation is not sufficient to make a functional protein, polypeptide chains are modified after translation and completed proteins are targeted to specific sites in the cell
free
___ ribosomes mostly synthesize proteins that function in the cytosol
bound
___ ribosomes make proteins of the endomembrane system and proteins that are secreted from the cell
signal
Polypeptides destined for the ER or for secretion are marked by a ___ peptide
particle
A signal-recognition ___ binds to the signal peptide and the SRP brings the signal peptide and its ribosome to the ER
mutation
A ___ is a change in the genetic material of a cell or virus. This can occur from erros in DNA replication or exposure to mutagens (chemical / radiation)
point mutation
A ___ ___ is a chemical change in just one base pair of a gene. The change of a single nucleotide in a DNA template strand can lead to the production of an abnormal protein. Ex: sickle-cell disease
point
___ mutations within a gene can be divided into 2 categories: Base-pair substitutions and Base-pair insertions or deletions
base pair substitution
A ___-___ ___ replaces one nucleotide and its partner with another pair of nucleotides
silent
___ mutations have no effect on the amino acid produced by a codon because of redundancy in the genetic code
release
When termination occurs, the mRNA reaches a stop codon in the A site called the ____ factor